TMM-132-01-SM-S-RA-015_Datasheet PDF

Room, which later evolved into UML-RT, offers a corresponding construct in capsule. One of the characteristics of these building blocks is that they are self-contained, which is reflected by the fact that they are all active, i.e., they have their own thread of control.

This makes it easier to model distributed systems and to assemble the building blocks in different ways. Each building block can thus be viewed as a complete system by itself or can be used as a small part of a system. In UML 2.0, active classes are used to model agents and capsules.

TMM-132-01-SM-S-RA-015_Datasheet PDF

Interfaces play an important role in component-based design; the ordinary interface concept of UML is still supported but is called a provided interface” in UML 2.0. To complement it, the concept of a required interface” is added. Just as the provided interface defines the services that are implemented by a class, a required interface defines the services that the class needs in order to function properly.

Class development This way, it is possible to develop a class as a standalone entity whose environment is specified solely through interfaces. The concepts of provided and required interfaces are derived from SDL and provide the basis for supporting protocol roles and protocols in UML-RT, since a protocol role is essentially a combination of a required and a provided interface. Interfaces in UML 2.0 are further expanded to have attributes and to be able to deal with asynchronous communication through the reception of signals.

In both SDL and UML-RT the concept of an interaction-called a gate in SDL and a port in UML-RT-plays a prominent role. In UML 2.0, the port is simply typed by an interface and can be either required or provided. A port sits on the boundary of a class and can be viewed either from inside the class (white-box view) or from outside the class (black-box view). In the former case it represents a view of the environment of the class; in the latter it represents a view of the class as seen from the environment.

TMM-132-01-SM-S-RA-015_Datasheet PDF

The primary purpose of a port, however, is to act as a connection point when classes are connected to each other as parts of an internal structure. In that regard, it can be viewed as a role that is played by the class in a particular interaction.

A composite port comprises a collection of required or provided ports and is used to model when a port is typed by multiple interfaces or when a port should support bidirectional communication. The latter occurs when a composite port has both required and provided ports. Ports are usually named by their typing interfaces, but composite ports have to be given a name of their own.

TMM-132-01-SM-S-RA-015_Datasheet PDF

So far, we have been talking only about the definition of classes. We next get to how each class can have an implementation that is made up of an internal structure that may be coupled to a behavior. In the simplest case, the implementation of a class is given directly by a behavior such as a state machine. In more complex cases the (containing) class may have an additional internal structure, which is made up of classes that are used as parts of the containing class and connected with each other in accordance with their ports and interfaces. Only classes that have matching interfaces may be connected to each other.

A part in UML 2.0 represents a usage of a class in a specific context; the same class can be used differently within other contexts or may even define other parts within the same context. A connector is used to indicate legal communication paths between parts. The paths can be considered contextual associations, since they are only applicable within the internal structure in which they are defined. We earlier talked about compositional building blocks; when an instance of a class is created, instances will also be created for each part in its internal structure according to the multiplicity of the part.

SDR solutions, in particular, are DSP applications due to the large amount of signal processing required for baseband implementation. Programmable DSP represent just fewer than 35% of the total DSP market and about 55% of programmable DSPs are used in wireless communications. Typically, fixed function ASICs have been required to implement wireless baseband processing. The SDR solutions move this function into software programmable platforms. Therefore, the total market for efficient SDR solutions may be anticipated to be large.

A significant market trend for 3G wireless communications is Java execution. Future 3G wireless systems will make significant use of Java. A number of carriers are already providing Java-based services and may require all 3G systems to support Java.

Previous communications systems have been developed in hardware due to the high computational requirements. DSP's in these systems have been limited to speech coding and orchestrating the custom hardware blocks. In high-performance 3G systems, there may be over 2 million logic gates to implement the system. A complex 3G system may also take many months to implement. After logic design is complete, any errors in the design may cause up to a 9-month delay for correcting the bugs and refabricating the device. This labor intensive process is counter productive to fast handset development cycles. The Sandbridge's design team has taken a completely new approach to communications system design.

Rather than designing custom blocks for every function in the transmission system, the team has implemented a processor capable of executing operations appropriate to broadband communications. The small and power efficient core is then highly optimized and replicated to provide a platform for broadband communications. This approach scales well with semiconductor generations and allows flexibility in configuring the system for future specifications and any field modifications that may be necessary.

The process involves designing the communications system in Matlab, thus ensuring the bit and block error rates for the transmission system are achieved. The Matlab system design is then ported to fixed point C code. From that point, no further programmer intervention is required. Sandbridge's highly optimizing compiler extracts the parallelism in DSP operations and optimizes performance on the SandBlaster DSP.


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